Optimal structural design of compliant mechanisms (consideration of quantitative displacement constraint)

Abstract

Structural optimization using the homogenization method which was introduced by Bendsøe and Kikuchi in 1988 is established as a theory of optimal design of layout (topology and shape). This theory has been applied to the various kind of problems, especially in meso-micro-scale design, for example in the microstructure of composite and piezo-ceramic material. Frecker and Nishiwaki studied the possibility of the extension of the homogenization design method for topology/shape optimization for elastic structures into the design of flexible structures such as compliant mechanisms. Compliant mechanisms is a relatively new breed of jointless mechanism in which elastic deformation is intended to be a source of motion. In the past, most flexible structural design optimization was considered only for the direction of the flexible point, by using the material density or equivalent homogenization method to identify the optimum layout. Here we shall extend it to the case of a two dimensional design for compliant mechanism which control the deflection of the flexible point. Moreover we also applied the image-based design method to extract a FE model for prototype from the optimal layout and propose the integrated structural design methodology.